A Wellington College pupil has been forced to sit his exams at another school after he used a teacher's account to download a massive amount of data.

The Year 13 pupil had accessed a teacher's log-in details and downloaded between 650 and 700 gigabytes, the school confirmed. That would be equivalent to more than 166,000 average music files.

Wellington College headmaster Roger Moses said the boy was asked to sit his exams at Wellington High so as to "maintain the integrity of our database", as there were concerns he might be able to access material that was sensitive to the school.

"The decision has been made. We want him out of the place. We don't want him accessing anything here."

The pupil had finished his school year with just externally assessed exams to go, so he was not expelled.

"I mean, the boy has left school. It's not like he's actually returning to the college at all. He's just sitting his exams somewhere else."

Mr Moses refused to elaborate on what the pupil had downloaded, or how he had accessed the teacher's log-in details.

However, he said the pupil could not have accessed exam papers because those were managed and distributed by the Qualifications Authority, not the school.

The college's internet connection is much faster than the standard home connection, but using it to download vast amounts of material is in breach of the school's acceptable usage policy for internet.

The amount of data the pupil downloaded is many times the monthly cap on most home broadband plans. By comparison, on TelstraClear's most expensive internet-only broadband plan, it would take 14 hours of continuous downloading at maximum speed to download 650GB - which is equivalent to 166,400 average-sized song files.

Wellington High School principal Nigel Hanton said Wellington College had made "a personal request" for the student to sit exams there towards the end of last week.

"As neighbours and educational colleagues there are times when we make requests of the other for support.

"As we knew there would be some capacity in our exam centre we agreed to help out."

NZQA chief executive Richard Thornton said it was not unheard of for students to sit exams at premises other than their home school, though NZQA did not have precise figures.

"In exceptional circumstances a student may request to sit an examination at another school . . . Each request is considered on a case-by-case basis."

Distance learners, or students at schools too small to be examination centres, sat their exams at the closest one to their home, said Mr Thornton.